This paper reports on some aspects of a ENI Group feasibility study of high pressure (> 100
bar) - high strength pipelines designed for transportation of large quantities of natural
gas over long distances (> 2500 km). The experimental results obtained in collaboration
with Centro Sviluppo Materiali (CSM) and ILVA L.T. clearly showed the full reliability of
modern high strength linepipe materials of X70-X80 grade, with respect to fracture
behaviour, even at low temperature, in very high pressure regimes.